Effect of initial excitation in the photofragmentation of model HCN and DCN. Comparison between approximate and exact calculations

Abstract
In this paper we present calculations for direct photodissociation and predissociation for model linear HCN and DCN. We compare the detailed product‐vibrational state distributions and absorption spectra as obtained by a ’’half‐collision’’ approximate scheme and an exact numerical integration of the coupled equations. It is predicted that large isotope effects can be encountered in certain regions of the spectrum for direct photodissociation of vibrationally excited molecules.